[RobertLByrd]

We have a new product for the RC industry that is ready to be prototyped before going to full production. We need 2-3 Prototypes cut and if they check out, meaning fit correctly and the machining work is clean we will be ready to go to production. I estimate production requirements to be 75-125 units per month and we are in a hurry to get these to market. We will probably buy in 100 lots for the first lot or two in case we need to make design changes based on customer feedback. After that we will increase order sizes to reduce administrative overhead and get the machining costs down.

To protect our designs, we require a Non Disclosure Agreement for all vendors so download the NDA and fill it out and fax it per the instructions at the bottom of the NDA. Be sure to e-mail me after you fax it and I will send the .dwg files and more renderings to you upon recipt. You can download the NDA here.

If you have any questions, feel free to e-mail me, but I can't go into specifics without the NDA on file.

Here is a photo of the part:


We need seperate bids on the prototyping work and the production work.

[caitolly]

Robert,
Have you considered using a casting?
The initial mold may run about 3k, but after that your per piece may only be a couple dollars each.
Just so happens I do that kind of work.
I design and build the mold (lost wax) and have my foundry pour the metal.
There will be a minimum of machining, hey I can do that too!

caitolly

PS: Please see my ad in the classified section, here on the CNC Zone

[lerman]

That looks like a perfect part for an extrusion. With some followup machining.

Ken

[skippy]

I agree with Ken. Going with an extrusion will be the most economical for you motor heatsink if that's what it is. (a) I wouldn't even bother to machine back the two side mounting tangs as per your drawing, just leave them going from front to back of your extrusion and (b) the front part which I imagine is to stop the motor from moving frontwards or backwards which ever it may be, does it really need that? If you make the extrusion slightly undersize in the internal diameter the clamping effect should be more than enough to hold the motor. The end result is a very economical part with the only machining required being to drill the two holes.
Skippy

[RobertLByrd]

I'm not opposed to using a partial extrusion process, but the rear wall is required to position the motor properly. The walls must be loose enought to accomodate a variety of motors as they vary slightly. there is another bracket that holds the other ned of the motor keeping it in place. Leaving the mounting tabs long is not a bad idea, but I would prefer them to be cut as per the drawings.

[ViperTX]

geesch....a motor heatsink........extrude it.....dies....I'm guessing under $2K......

Oops...just noticed a wall where the motor rests against.....and the bored mounting.....hmmmmmm.....a casting is probably your best bet with 2 post casting operations......mill the wall to give you a flat surface and bore the hole......

[RobertLByrd]

That may be practical depending on how well it sells, but first we need the prototypes to allow us to test the concept, and then we need a production run of 100 to test the market.

[HuFlungDung]

Any way to redesign that part so that you can use a stock cpu heatsink, or some such? That way, perhaps you'd only have to deal with machining the saddle part of the product. Be a nice way to keep costs down for the prototypes, anyways.

[RobertLByrd]

We want it to be one piece for the best heat transfer possible.

[tizank]

We want it to be one piece for the best heat transfer possible.

copper thermal conductivity is greater than AL!

[RobertLByrd]

Yes, but it is my understanding that copper is more difficult to machine and more expensive. Is this true?

[Ken_Shea]

Yes, but it is my understanding that copper is more difficult to machine and more expensive. Is this true?

Yes and Yes, both would add to substantially higher item cost, it is also much heavier if weight is a concern.

There is some free machining copper but I have no experience with it.

[DareBee]

Free machining brass is wonderfull. I would think copper would be ok too.

[HuFlungDung]

You guys best tell him that "free machining" metals still cost something to cut, or he might think you're ripping him off on the price

[tizank]

Yes, but it is my understanding that copper is more difficult to machine and more expensive. Is this true?

"Difficult to machine" As far as my experiance with Cu; with the right angles, rakes on your cutting tools(neutral maybe negative rakes) and lubricating coolants cuts wonderfull... and yes Cu its about 1/4 more expensive than AL....